In 387, the eastern Roman empire experiences a general uprising following Theodosius's edict to raise taxes.
Taking advantage of riots in major cities throughout the eastern Roman empire,[5] Maximus invades Italy.
[6] Maximus, in the meantime, had marched part of his army to Siscia commanded by Andragathius,[9] blocking Theodosius's advance into Italy.
[11] Theodosius's cavalry, consisting of Alans, Goths, and Huns, charged across the Sava river directly at Maximus's forces.
[9] Theodosius continued his march and met Maximus's army under the command of his brother, Marcellinus, at Poetovio.
Finally Theodosius's infantry gained the upper hand and Maximus's troops either capitulated or fled.
[14] After his decisive victory Theodosius, following in swift pursuit, besieged Maximus in his refuge of Aquilia, a fortress west of the Julian Alps.